Colo. Const. art. XXVIII, § 6

(1) Any person who expends one thousand dollars or more per calendar year on electioneering communications shall submit reports to the secretary of state in accordance with the schedule currently set forth in 1-45-108 (2), C.R.S., or any successor section. Such reports shall include spending on such electioneering communications, and the name, and address, of any person that contributes more than two hundred and fifty dollars per year to such person described in this section for an electioneering communication. In the case where the person is a natural person, such reports shall also include the occupation and employer of such natural person. The last such report shall be filed thirty days after the applicable election.

(2) Notwithstanding any section to the contrary, it shall be unlawful for a corporation or labor organization to provide funding for an electioneering communication; except that any political committee or small donor committee established by such corporation or labor organization may provide funding for an electioneering communication.